Atropetae

This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

Introduction

Infraorder Atropetae includes families Lepidopsocidae, Psoquillidae, and Trogiidae and comprises 31 genera and about 300 species distributed worldwide. The North American fauna includes 25 species from 13 genera.

Characteristics

Synapomorphies

In the female:

The ovipositor is composed of the elongated external valves of the gonapophyses joined together at midline by a membrane.

The presence of glandular accessory bodies in the spermathecal sac.

General Characters

Head:

Head is short and broad.

Antennae have more than 18 segments without ringed sculpturing (annulations).

Ovipositor is composed of the fused, elongate external valves of the gonapophyses.

Spermathecal sac has one or two glandular accessory bodies.

Male:

Paraproct has an anal spine.

Phallosome is composed of two arms that are never fused anteriorly.

Discussion of Phylogenetic Relationships

Monophyly of infraorder Atropetae is supported by two characters of the female genitalia: the ovipostior composed of the elongated external valves of the gonapophyses joined together at midline by a membrane, and the presence of glandular accessory bodies in the spermathecal sac. Molecular analysis of nine species of Atropeae also supports the monophyly of the infraorder and indicates a sister relationship between families Trogiidae and Psoquillidae (genes 18S & Histone3 nDNA, 16S rDNA; Yoshizawa et al. 2006).

Each ToL branch page provides a synopsis of the characteristics of
a group of organisms representing a branch of the Tree of Life. The
major distinction between a branch and a leaf of
the Tree of Life is that each branch can be further subdivided into
descendent branches, that is, subgroups representing distinct genetic
lineages.